Ethylenediaminetetraacetic acid induces antioxidant and anti-inflammatory activities in experimental liver fibrosis.

BACKGROUND: Experimental liver fibrosis induced by carbon tetrachloride (CCl(4)) is associated with oxidative stress, lipid peroxidation, and inflammation. This work was focused on elucidating the anti-inflammatory and antioxidant effects of ethylenediaminetetraacetic acid (EDTA) in this model of hepatotoxicity. METHODS: Wistar male rats were treated with CCl(4) and EDTA (60, 120, or 240 mg/kg). Morphometric analyses were carried out in Masson's stained liver sections to determine fibrosis index. Coagulation tests prothrombin time (PT) and partial thromboplastin time (PTT) were also determined. Gene expression for transforming growth factor beta (TGF-beta1), alpha1(I) procollagen gene (alpha1 Col I), tumor necrosis factor alpha (TNF-alpha), interleukin-6 (IL-6), and superoxide dismutase (SOD) was monitored by real-time PCR. Antioxidant effect of EDTA was measured by its effects on lipid peroxidation; biological activity of ceruloplasmin (Cp), SOD, and catalase (Cat) were analyzed by zymography assays. RESULTS: Animals with CCl(4)-hepatic injury that received EDTA showed a decrement in fibrosis (20%) and lipid peroxidation (22%). The mRNA expression for TNF-alpha (55%), TGF-beta1 (50%), IL-6 (52%), and alpha1 Col I (60%) was also decreased. This group of animals showed increased Cp (62%) and SOD (25%) biological activities. Coagulation blood tests, Cat activity, and gene expression for SOD were not modified by EDTA treatment. CONCLUSION: This study demonstrates that EDTA treatment induces the activity of antioxidant enzymes, decreases lipid peroxidation, hepatic inflammation, and fibrosis in experimental liver fibrosis induced by CCl(4).

Combinatorial gene therapy induces regression of hepatic encephalopathy.

Capillarization of the sinusoid impedes the clearance of neurotoxic substances in liver fibrosis. These events may result in hepatic encephalopathy. Neurological and hepatic features of rats after bile duct ligation (BDL) supplemented with Manganese (BDL+Mn(2+)) were examined. The 4-week-old BDL rats had elevated levels of ammonia and were concomitantly fed with 1 mg ml(-1) of MnCl(2) in drinking water (BDL/Mn(+2)). Five out of fifteen rats were killed and the serum, liver and brain tissue (striatum and substantia nigra) were recovered. Of the remaining BDL/Mn(+2)-cirrhotic animals (n=10), five were injected with a combination of Adenovirus-human plasminogen activator (Ad-huPA) and Adenovirus-matrix metalloproteinase-8 (Ad-MMP-8) (3 × 10(11)+1.5 × 10(11) vector particles per kg), and five with 4.5 × 10(11) vector particles per kg of Adenovirus-ß-galactosidase (Ad-ß-Gal). This treatment was carried on for 10 days. The BDL/Mn(+2) rats displayed tremor, rigidity and gait abnormalities, which improved notably with combinatorial gene therapy, as well as motor coordination. Liver fibrosis was evidently less after treatment with Ad-huPA+Ad-MMP-8 (25%). In the brain (striatum), Ad-huPA+Ad-MMP-8 treatment rendered higher concentrations of dopamine compared with Ad-ß-Gal-treated encephalopathic rats (210 and 162 ng g(-1) of tissue, respectively). The BDL/Mn(+2) animals and controls treated with Ad-ß-Gal showed abnormal morphology in astrocytes (gliosis) in striatum and substantia nigra, in which expressions of green fibrillar acidic protein and tyrosine hydroxylase were altered. These abnormalities decreased with Ad-huPA+Ad-MMP-8 treatment. Importantly, the latter animals showed an increment in sprouting of nervous fibers in substantia nigra. Combinatorial gene therapy improves neuroanatomical and neurochemical characteristics similar to human hepatic encephalopathy.